Semiconductor laser driving apparatus utilizing three current sources to control read and write light power
US5568464A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Nov 17, 1994 |
| Grant date | Oct 22, 1996 |
| Priority date | — |
| Expiry date | Nov 17, 2014 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01S5/06832
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A semiconductor laser driving apparatus for use in an information recording/reproducing apparatus that records and reproduces information by illuminating a medium with a laser beam. The semiconductor laser driving apparatus includes a semiconductor laser for generating the laser beam, a photo detector for detecting the output of the semiconductor laser, a first current source for generating a base optical power of the output of the semiconductor laser wherein the base optical power is used in recording information, a second current source for adjusting a reproducing optical power of the output of the semiconductor laser wherein the reproducing optical power is used to reproduce information, a third current source for adjusting a recording optical power of the output of the semiconductor laser wherein the recording optical power is used in recording information, and an optical power control circuit for controlling the optical output power of the semiconductor laser in such a manner that the reproducing optical power used to reproduce information is generated by the sum of a current provided by the first current source and a current provided by the second current source, the recordin…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.